Electromagnetic step-by-step switch



Nov. 28, 1950 ELECTROMAGNETIC STEP- BY STEP SWITCH Filed Nov. 27, 1946 C. l. JOHNSON ETAL Sheets-Sheet 1 INVENTORS 60 97" I. JOHNSON AGENT Nov. 28, 1950 c. m. JOHNSON ETAL ELEC'I'ROMAGNETIC STEP-BY-STEP swITcH 2 Sheets-Sheet 2 Filed Nov. 27, 1946 INVENTORS CU/PT I. JOHNSON BY lf/LPL 1?. 67/9056 Patented Nov. 28, 1950 ELECTROMAGNETIC STEP-BY-STEP SWITCH Curt I. Johnson and Karl R. Stauss, Vestal, N. Y., assignors to International Business Machines Corporation, New York, N. Y., a corporation of New York Application November 21, 1946, Serial No. 712,586

2 Claims. 1

This invention relates to devices whereby a series of electrical circuits may be established in single step increments under actuation of an electrical impulse delivered from a remote point.

More specifically this invention relates to selective switches or relays, particularly to stepping relays capable of functioning as impulse accumulators, distributors or counters wherein the required actuating impulse is of short duration and uses a minimum expenditure of electrical energy.

Stepping relays commonly are operated by a solenoid and linkage arrangement whereby a conductive arm is advanced by increments to contact successively a series of conducting points along a predetermined path. The energy required to move the conductive arm for each successive step is provided by the solenoids. An example of a stepping relay of this type is found in U. S. Patent 1,569,450. These devices consame a considerable amount of electrical energy which is provided by either a heavy current for a short duration or a lighter current for a longer duration. In some stepping relay applications neither of the aforementioned conditions can be tolerated without sacrificing emciency.

In electrical accounting machines, for example, where stepping relays frequently are used as impulse accumulators it is essential to have high speed operation. Consequently, stepping relays have to be operated using a relatively heavy current for each incremental operation. Excessive wear is encountered frequently in the moving parts, and the current consumed by a plurality of such relays operating in parallel may be damaging to the devices initiating the actuating impulses. Constant operation at high speed in such machines results in further operational difliculties so that stepping relays have to be replaced frequently.

The present invention is concerned with improvements in stepping relays so that the diffl culties mentioned above may be avoided. These improvements have become feasible by taking advantage of the characteristic cyclic operation of devices, such as electrical accounting machines, in which during one part of the operating cyclerelays are conditioned to receive im pulses wliil"'dirring another part of the operating cycle they maybe insensitive. It is, accordingly, an object of this invention -to provide an improved stepping relay capable of high speed operation under actuation of an electrical impulse of short duration and small magnitude.

It is a further object of this invention to provide an improved stepping relay in which the energy required for operation over a plurality of steps is stored at one time for release in incremental amounts by actuating impulses to cause operations at other times.

It is another object of this invention to provide a st pping relay of improved construction and arrangement of parts wherein the wear upon moving parts is reduced to a minimum.

It is still a further object of this invention to provide an improved stepping relay in which the actuating impulse for each incremental operation represents only a small percentage of the energy released at each operation.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings, which disclose, by way of example, the principle of the invention and the best mode, which has been contemplated, of applying that principle.

In the drawings:

Fig. 1 is a top view of the stepping relay showing the circuit establishing contacts and the distributing arm assemblies.

Fig. 2 is substantially the same as Fig. 1 with contact and distributing arm assemblies removed.

Fig. 3 is a partial side elevation view of Fig. 2 to illustrate details of the impulse actuating mechanism.

Fig. 4 is a sectional view of Fig. 2 along the line 4-4 to which has been added a corresponding sectional view of the contact and distributing arm assemblies to show the relationship of the various elements of the operating mechanism.

With reference to Fig. 1, a rotatable distributor arm ii is mounted on a hollow shaft I! (see Figs. 2 and 4) by means of a clamping screw IS. The arm ll carries a pair of diametrically opposed brushes ll retained to the arm by the brush holders IS. The brushes it ride on the inner perimeter of an insulated contact ring it to contact respectively, an inserted common conductive segment i1, occupyin approximately degrees 01' the contact ring [6, and any one of ten (10) inserted contacts l8 equally spaced about the remainder of the ring it. A lug I9 is provided for each contact I8 so that circuit connections can be made. A lug i9 is provided for the common conductive segment I! for the same purpose. The remainder of the mechanism, hereinafter described, operates in a manner to rotate the arm ll so that the brushes it close a circuit selectively between the segment I1 and any one of the contacts to in step by step flashion according to electrical impulses received from a remote point thereby actuating the mechanism. For example, if the arm it is resting in its normal position so that one brush it contacts the common segment ill and the other brush to contacts the contact id corresponding to the lug it marked A and two actuating impulses are delivered to the actuating mechanism, the arm it will rotate by increments in a clockwise direction successively contacting the contacts corresponding to lugsas marked B-and and will remain on the contact corresponding to the lug it marked "6 until additional actuating impulses are received by the mechanism which is also capable of returning the arm ii to its normal position by reversibly rotating it in a counterclockwise direction according to other impulses received by the mechanism. The ring it is mounted to the frame to by means of a screw and two aligning studs 22 which engage elongated holes 23 in the ring it.

The remainder of the mechanism is illustrated principally in Fig. 2 and detailed in Figs. 3 and i. A ratchet segment to is fastened to the hollow shaft it to which also is attached a gear 25 which in turn meshes with an idler gear segment 25 which is mounted on a shaft 21. The shaft 2? is fastened to a portion of the mounting 28 to which the frame 20, previously mentioned, is also attached. Also mounted onthe shaft 21 is an idler gear 29 which is pinned to the gear segment 26. The gear 29 meshes with a gear segment 36 which is fastened to a shaft 3! coaxially aligned and partly contained within the hollow shaft 52 and supported by a. bearing 32 in the mounting 28. The mounting serves also to act as a magnetic yoke for a coil 33 which is located within the mounting partially surrounding the shaft 3| which, together with a hollow core 34, provides the central core for the coil 33.

An armature 35 also is aflixed to the shaft 3| and arranged so that when coil 33 is energized the shaft 3| will be rotated coimterclockwise (as viewed in Fig. 2) as the armature 35 rotates to embrace the greatest amount of flux between the faces of the magnetic yoke represented by the mounting 28. A pin 36 is located in one lobe of the armature 35 to which one end of a. spring 31 is fastened. .The opposite end of the spring 31 is attached to a bracket 38 which in turn is Si is in tension as a result of the action of the armature 35, previously described. The escapemerit pawl so normally is held free from the ratchet segment 25 by a spring 33. Cine end Silo, of the pawl lt engages with the free end of an armature 6d which is pivoted at its other end on a stud 35 in a sub frame 16 which is mounted to the frame 20. When the armature 35 rotates counterclockwise the spring 31 is stretched so that a tensional force is set up in the spring 31, tending to rotate the armature in a clockwise direction. Since the gear segment 30 is fastened to the armature shaft (shaft 3|) and is pinned to the armature 35 it follows that any tendency for rotation of the armature will be transmitted to the hollow shaft l2 via. the

gear train gear segment 30, idler gear 29, idler.

gear segment 26, and gear 25. Consequently, the shaft [2, and the gear 25, the ratchet segment 24 and the distributor arm] I, all attached thereto, will be rotated in the same direction as'the armature 35. The gear ratios are selected so that for approximately 90 degrees of rotation of the armature 35, the shaft l2 and its aforementioned components will rotate 180 degrees.

Attached to the mounting 28 is a stud 39 which carries an escapement pawl 10 and a. stop pawl 4| bothof which are engageable with ratchet segment 24. Normally the stop pawl ll engages the ratchet segment 2| under the urging of a attached to the mounting 28. A coil all having a core it attached to the frame 35 is energized to move the armature l l to the left (as viewed in Fig. 3 or" the drawings).

The operation of the device is as follows: Assuming that the arm it is positioned as shown in Fig. 1 (solid lines) with the brushes it respectively resting on the conductive segment ill and the contact l8 corresponding to the lug is marked l-i," and that the armature 35 has been acted upon by the coil 33 to assume the position shown in Fig. 2 to cause the spring st to have tension tending to rotate the armature 85 clockwise an electrical impulse is delivered to the coil L l from a remote point. The armature l l will be attracted thereby engaging, the end :lllc of the escapement pawl ld which will be rotated clockwise about the stud 39 against the tension of the spring 63 to engage its forked end with a pin in the stop pawl di to rotate it about the stud 39 also in a clockwise direction. The pawl Ml engages a tooth in the ratchet segment 25 as the stop pawl ii is pulled free and the ratchet segment 241 rotates clockwise under the urging of the spring Bl acting on the armature 35 through the gear train previously discussed in detail. Following the impulse the armature it is restored to its normally open position so that the end ida of the pawl do is no longer engaged and the stop pawl s: engages the ratchet 24 at the tooth following the one it previously engaged as the pawl so returns to its normal position under the urging of the spring 58. The

arm it will be rotated clockwise to advance the Ibrushes i l to contact, respectively, the segment l1 and a contact 58 corresponding to 9. lug is marked 3. When four (4) more impulses are received by coil ll the action just described will be repeated for an equivalent number of times until after the fifth impulse the arm ii and the brushes i l will rest asshown by the dotdash lines in Fig. 1 so that the brushes it contact respectively the segment ill and the contact l8 corresponding to a lug it marked F.

At such a time in the operative cycle of the apparatus, to which the present invention is applied, when the present device is no longer required to be sensitive to actuating impulses, an electrical impulse is delivered; to the coil 33. When coil 33 is energized the armature 35 is rotated counterclockwise, as previously explained, and the shaft 52, together with the ratchet 24 and the arm H, is rotated similarly until the brushes id of the arm ii return to their original positions as viewed in Fig. 1. A stop 50 (see Fig. 2) is provided so that the armature 35 does not overrun its initial position. The ratchet 24 retains the shaft. i2 from rotating in a clockwise direction by virtue of the stop pawl 4| which is cammed out of the way by the ratchet teeth when the ratchet 24 rotates counterclockwise. The spring 31 is stretched to store up energy to repeat its operation thereby conditioning the device to respond to actuating impulses delivered to the coil 41 as originally.

It can be readily understood that neither the magnitudenoTtbe duration of the actuating imspring 42 to prevent its rotation when the spring pulse'delivered to the coil 41 need be large, since the energy required to pull the armature 44 to trip the pawl 40 is obviously small in quantity compared to that required to rotate the arm II and the brushes H, the latter energy being provided by spring 31 from energy stored when the spring is stretched by the armature 35. Consequently, the present invention provides a device in which energy stored prior to operation can be released in single increments to furnish high speed impulse operation.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to a preferred embodiment, it will be understood that variou omissions and substitutions and changes in the form and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention. It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimed is:

1. A rotary selective switch including a series of fixed contacts spaced in an arcuate path and a movable contact operable to engage the said fixed contacts in a predetermined sequence, a rotary member for carrying the said movable contact, a spring normally biasing the said member to position the movable contact at one extremity of the said series 01 coacting and rotating with the said member, an electromagnet adapted to set up magnetic fiux in the said armature for rotating it and the said member against the bias of the said spring to move the said fixed contact to the other extremity of the said series each time the electromagnet is energized, and means for releasing the movfixed contacts, an armature able contact from the said other extremity under the influence of the said spring for step by step engagement with the said fixed contacts.

2. A rotary selective switch including a series of fixed contacts spaced in an arcuate path and a movable contact operable to engage the said fixed contacts in a predetermined sequence, a rotary member for carrying the said movable contact, a spring normally biasing the said member to position the movable contact at one extremity of the said series of fixed contacts, means for rotating the said member consisting of a rotatable armature arranged coaxially with the said member and a field winding surrounding the said amature, the said field winding being adapted, upon being energized, to set up flux to rotate the said armature and the said member against the bias of the said spring to position the movable contact at the other extremity of the said series, and means for releasing the movable contact from the said other extremity under the influence of the said spring for step by step engagement with the said fixed contacts.

CURT I. JOHNSON. KARL R. STAUSS.

REFERENCES CITED The following references are of record in the file of this patent:

Hayslett et al May 14, 1946 

